You can see where we put the tube to daylight. It runs down slope and actually into the iceplant that borders our property outside of the fence. We live in a very rural area so if the tube is needed I'm not concerned about where the water will exit.
The bricks are made locally in giant wood ovens from a mix of mud and straw. They are very light and very hard. I spent many hours online and on the phone trying to locate a pumice source with no avail. The closest I got was that we needed to hike up into the Andes and collect it ourselves. When I finally found out we could use the brick as a substitute it was such a relief. In total we used 500 bricks (here they cost $100 pesos each when delivered).
We thought to do a simpler infiltrator, but at the same time I wanted access to the chamber in case of clogging. With rental cabins you have to think of the worst case scenario (kid's throwing toys or adults throwing condoms down the toilet). To have access we needed a lid at the height of the walkway. Cement, although a bit more expensive, seemed to be the most structurally sound way of doing the infiltrator. More photos on the next post.